This invention relates to a method and apparatus for cleaning paint spray guns. In particular, the invention relates to an apparatus for cleaning spray guns, including a novel cover member for allowing the paint spray guns to be easily maneuvered into and positioned within the apparatus for cleaning thereof.
Paint spray guns are used in a variety of industries to project paint onto an object. In the automobile industry, a particular paint spray gun may be used to spray a number of paint coats of different colours onto parts for automobiles. The paint spray gun must be regularly cleaned to remove curing and dry paint in the nozzle end of the spray gun, and prior to the use of paint of a new colour, to remove remnants of the first paint.
Paint spray guns are cleaned by projecting solvents at high velocity at the paint spray guns contained within an apparatus. The high velocities are required to remove dried paint from the nozzle end of the gun. The cleaning is effected in a separate vessel to prevent leakage of spent solvent.
U.S. Pat. No. 4,830,882 discloses a method and apparatus for cleaning paint spray guns which includes a cleaning tank and two flexible cover members having holes for inserting a paint spray gun therethrough. A plurality of cleaning nozzles are disposed within the cleaning tank to project a cleaning fluid onto the paint spray gun to clean the paint spray gun. The arrangement of the cleaning nozzles within the cleaning tank does not necessarily provide a full cleaning of the paint spray gun since full cleaning depends upon the placement of the cleaning nozzles within the cleaning tank and the angle at which the cleaning fluid is projected onto the paint spray gun. Also, the requirement that the nozzles must be appropriately arranged to effectively project cleaning fluid at the paint spray gun makes the apparatus complicated for manufacture and repair.
The disadvantages of the prior art may be overcome by providing an apparatus for cleaning a spray gun having a rotating spray nozzle for projecting a cleaning spray and a rotational nozzle for projecting a spray to effect rotation and to wet an interior surface of containment vessel.
It is desirable to provide a method of cleaning a paint spray gun in a cleaning vessel, comprising the steps of positioning the paint spray gun within the cleaning vessel, rotating a plurality of cleaning nozzles and applying a spray of cleaning fluid through the plurality of nozzles at the paint spray gun; purging the nozzles for cleaning fluid; and applying air to the paint spray gun through the spray nozzles to dry the paint spray gun.
Accordingly to another aspect of the invention, there is provided a method of cleaning a nozzle of a spray gun. The steps comprise positioning a nozzle of a spray gun in a port of a vessel in a sealing relation. Initiating a fluid flow of a first fluid through a rotatably mounted impeller having a cleaning nozzle and a rotational nozzle. The fluid flow through the cleaning nozzle effects an offset cleaning spray directed at the spray gun and the fluid flow through the rotational nozzle effects rotation of the impeller and wets an interior surface of the vessel. Collecting the fluid from the vessel. Initiating the fluid flow with a second fluid for purging the impeller of the first fluid.
According to one aspect of the invention, there is provided an apparatus for cleaning spray guns has a closed vessel having an inlet, a drain and port for receiving a nozzle of a spray gun. A spray impeller is rotatably mounted within the vessel and in fluid communication with the inlet. The spray impeller has an offset cleaning nozzle for projecting a cleaning spray towards the spray gun and a rotational nozzle for projecting a rotational spray to effect rotation of the spray impeller. The port has a seal for sealingly receiving the spray gun and positioning the nozzle of the spray gun in the cleaning spray.
According to another aspect of the invention, there is provided a cover member which enables a paint spray gun to be easily maneuvered into and positioned within the apparatus.
The method and apparatus of the invention provides a number of advantages. First, the interior of the cleaning vessel is continuously cleaned by the cleaning fluid expelled by the cleaning and rotational nozzles. Second, the paint removed from the paint spray gun and the solvent required for cleaning do not escape to the surrounding environment. Third, 360xc2x0 coverage and the direct impingement angle afforded by the rotating impeller design provide a more effective removal of paint from the paint spray gun. Fourth, the apparatus is easily repaired and requires relatively low maintenance compared to existing apparatus for cleaning paint spray guns.